Separation and services provided

• When ATC is provided, the ATC is responsible for separation, otherwise the pilot
• They go from more responsibilities for the ATC to fewer
• ATC responsibilities are loosened on the VFR side first
• In controlled airspace, you get ATC or traffic information
• In uncontrolled airspace, you get FIS

Class A

Only IFR is allowed

Class B

VFR is also allowed

Class C

Loosen VFR/VFR

Instead of ATC, VFR will get traffic information and, if requested, traffic avoidance advice

Class D

Loosen VFR/IFR

Class E

Communication is no longer required for VFR

ATC can no longer guarantee anything in regard to VFR, so the traffic information is only "as far as practical". ATC will also stop giving traffic avoidance advice.

Class F

Uncontrolled airspace

This is uncontrolled airspace, so traffic information becomes FIS.

This is uncontrolled airspace, so ATC has no authority. They can only separate IFR from IFR by providing air traffic advisory service. Therefor, the separation is only "as far as practical".

Class G

Free-for-all

Speed limitation

When the pilot has some responsibility for separation, then a speed limit of 250 KIAS is in place under FL100.

One way to think of it, is like this. The speed limit is there for the general aviation, and they typically do not fly above FL100. We also need enough time to react when we see another plane, this becomes difficult when they fly very fast.

Radio communication

It's always required for IFR, but for VFR, it's only required for classes B, C and D.

Remember, the big feature about class E is that radio communication is no longer required for VFR.

Clearance

You always need clearance in controlled airspace, except for VFR in class E.

VFR can't ask for clearance because they don't always have a radio